Sending it back is a smart move. I was having trouble with one of my NM66 Combat Magnums where the trigger was "knuckling", or stacking, right at the end of the trigger pull before the hammer breaks forward. Unbelievable... I had it back in under 2 weeks from the time I shipped it, and S&W did a perfect job, even touching up a couple birth marks I noted on the glass beading finish! I couldn't be more pleased.

FWIW, on both my NM 66 Combats, I installed the Wilson Combat spring kit, along with the 13# trigger return spring in the rebound slide. It's a very simple procedure that I can now do in maybe 15 minutes. I got that little revolver tool for the rebound slide, which makes removal/installation of the trigger return spring quick and easy. With no other polishing or monkeying around with the internals, I can't tell you how much that simple $20 spring change investment made for a completely different gun. If you live anywhere nearby and ever wanted to try it, I'd be more than happy to show you how.

Best of luck, if your experience with S&W is anything like mine recently was, you'll be pleased with the results.